<template>
  <div>
    <div class="type-nav">
      <div class="container">
        <div @mouseleave="moveIndex" @mouseenter="showTypeNav">
          <h2 class="all">全部商品分类</h2>
          <transition name="sort">
            <div class="sort" v-show="isShow">
              <div class="all-sort-list2" @click="goSearch">
                <div
                  class="item"
                  v-for="(c1, index) in categoryList"
                  :key="c1.categoryId"
                >
                  <h3
                    :class="{ cur: currentIndex == index }"
                    @mouseenter="changeIndex(index)"
                  >
                    <a
                      :data-category1Id="c1.categoryId"
                      :data-categoryName="c1.categoryName"
                      >{{ c1.categoryName }}</a
                    >
                  </h3>
                  <div
                    class="item-list clearfix"
                    :style="{
                      display: currentIndex == index ? 'block' : 'none',
                    }"
                  >
                    <div class="subitem">
                      <dl
                        class="fore"
                        v-for="(c2, index) in c1.categoryChild"
                        :key="c2.categoryId"
                      >
                        <dt>
                          <a
                            :data-category2Id="c2.categoryId"
                            :data-categoryName="c2.categoryName"
                            >{{ c2.categoryName }}</a
                          >
                        </dt>
                        <dd>
                          <em
                            v-for="(c3, index) in c2.categoryChild"
                            :key="c3.categoryId"
                          >
                            <a
                              :data-category3Id="c3.categoryId"
                              :data-categoryName="c3.categoryName"
                              >{{ c3.categoryName }}</a
                            >
                          </em>
                        </dd>
                      </dl>
                    </div>
                  </div>
                </div>
              </div>
            </div>
          </transition>
        </div>
        <nav class="nav">
          <a href="###">服装城</a>
          <a href="###">美妆馆</a>
          <a href="###">尚品汇超市</a>
          <a href="###">全球购</a>
          <a href="###">闪购</a>
          <a href="###">团购</a>
          <a href="###">有趣</a>
          <a href="###">秒杀</a>
        </nav>
      </div>
    </div>
  </div>
</template>

<script>

export default {
  name: "TypeNav",
  data() {
    return {
      //三级菜单需要用的属性
      currentIndex: -1,
      //控制TypeNav显示与隐藏
      isShow: true,
    };
  },
  computed: {
    ...mapState({
      categoryList: (state) => state.home.categoryList,
    }),
  },
  methods: {
    //修改当前是第几个一级菜单
    //函数节流：给浏览器有充裕的时间进行解析代码
    //注意回调写法：如果是箭头函数，他的上下文为undefined，需要的是组件实例，因为组件的实例身上才有currentIndex属性
    changeIndex: throttle(function(index) {
      this.currentIndex = index;
      console.log(index);
    }, 10),
    //鼠标移出【利用到了事件委派】
    moveIndex() {
      this.currentIndex = -1;
      //判断鼠标移上与移下的隐藏菜单是在search路由组件中发生
      if (this.$route.path != "/home") {
        this.isShow = false;
      }
    },
    //路由跳转
    goSearch(event) {
       //获取触发事件的元素【可能是h3、a、div、em、dt、dl】
      let targetNode = event.target;
      //获取触发事件的元素的自定义属性【因为只有a标签才有自定义属性】
      let data = targetNode.dataset;
      //解构出相应的的自定义属性与属性值【如果id、name有一定是a标签】
      let { category1id, category2id, category3id, categoryname } = data;
      //如果标签带有categoryname一定是a标签【不会是其他的标签】
      if (categoryname) {
        //准备路由跳转的数据
        let location = { name: "search" };
        let query = { categoryName: categoryname};
        //判断点击的是哪一个菜单
        if (category1id) {
           //一级菜单
          query.category1Id = category1id;
        } else if (category2id) {
          //二级菜单
          query.category2Id = category2id;
        } else {
          //三级菜单
          query.category3Id = category3id;
        }
        //将location与query对象合并
        location.query = query;
        //这里的路由跳转传递参数不严谨|需要把params参数也需要考虑进来
         //需要三级菜单跳转之前看一眼有没有params参数，如果有带上
         if(this.$route.params){
            location.params = this.$route.params;
            //进行路由跳转与传递参数
            this.$router.push(location);
         }

      }
    },
    //控制菜单显示与隐藏
    showTypeNav() {
      if (this.$route.path != "/home") {
        this.isShow = true;
      }
    },
  },
  //组件挂载完毕,判断isSHow初始值到底是true|false
  mounted() {
    //当search组件挂载成功的那一刻，将菜单隐藏
    if (this.$route.path != "/home") {
      this.isShow = false;
    }
  },
};
</script>

<style lang="less" scoped>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;
      &.sort-enter {
        height: 0px;
        opacity: 0;
      }
      &.sort-enter-active {
        transition: all 0.5s;
      }
      &.sort-enter-to {
        height: 461px;
        opacity: 1;
      }
      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }
          .cur {
            background: skyblue;
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}
</style>
